Prophylactic role of oral L-arginine on histological and contractile changes in a rat chronic bladder injury model.
BACKGROUND
The effect of L-arginine on bladder tissue structure and function in a rat bladder injury model were investigated.


METHODS
24 male Sprague-Dawley rats were used. The control group received a regular diet. The L-arginine group received oral L-arginine (1 g/day). The protamine sulfate (PS) group received intravesical PS every 48 h (0.5 ml, 5 mg/ml). L-arginine was administered to the PS+L-arginine group in addition to PS. At the end of 1 week, bladder tissues were processed for histological and functional studies.


RESULTS
The PS group revealed urothelial damage with glycosaminoglycan layer irregularity and mast cell infiltration which was not evident in the PS+L-arginine group. 120 mM potassium and electrical field stimulation (EFS)-induced contractions in the PS group were significantly lower than in other groups, whereas carbachol-induced contractions were not significantly different. Relaxation responses of precontracted strips to EFS and isoproterenol did not reveal a significant decrease in the PS group, whereas L-arginine significantly enhanced these responses in PS-treated animals.


CONCLUSIONS
Intravesical PS causes urothelial damage and inflammation that is associated with significant changes in rat bladder tissue contractility. Oral L-arginine treatment is found to prevent these histological and contractile alterations. Our findings may indicate the nitric oxide-cGMP pathway as a possible therapeutic target in various bladder diseases associated with urothelial damage.
Ozgür
Abdurrahman
A
Department of Urology, Marmara University School of Medicine, Istanbul, Turkey.
Onol
Fikret Fatih
FF
Ercan
Feriha
F
Tarcan
Tufan
T
D000284:Administration, Oral; D000318:Adrenergic beta-Agonists / Q000494:pharmacology; D000818:Animals; D001120:Arginine / Q000008:administration & dosage*; D002217:Carbachol / Q000494:pharmacology; D018679:Cholinergic Agonists / Q000494:pharmacology; D002908:Chronic Disease; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D004558:Electric Stimulation; D007545:Isoproterenol / Q000494:pharmacology; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects*; D009126:Muscle Relaxation / Q000187:drug effects*; D011188:Potassium / Q000378:metabolism; D011479:Protamines; D051381:Rats; D017207:Rats, Sprague-Dawley; D001743:Urinary Bladder / Q000187:drug effects* / Q000473:pathology / Q000503:physiopathology; D001745:Urinary Bladder Diseases / Q000139:chemically induced / Q000473:pathology / Q000503:physiopathology / Q000517:prevention & control*; D019459:Urothelium / Q000187:drug effects / Q000473:pathology
D000318:Adrenergic beta-Agonists; D018679:Cholinergic Agonists; D011479:Protamines; D002217:Carbachol; D001120:Arginine; D007545:Isoproterenol; D011188:Potassium